Description: FIELD OF THE INVENTION
[001] The present invention relates to edible coatings to be applied on fresh fruits, vegetables, animal feed, meat, or any other food surface. The edible coating is a synergistic combination comprising a glazing agent, an adjuvant, an emulsifier, an edible clay and microorganisms. 5
BACKGROUND OF THE INVENTION
[002] Post-harvest loss is a serious concern in fruits and vegetables, particularly when they involve long periods of transport and storage. To reduce post-harvest loss, surfaces of fruits and vegetables are coated with specialized compositions that 10 retain moisture, color, taste of the fruit or vegetable, particularly during long transport and storage. These compositions contain ingredients including, but not limited to, glazing agents, preservatives, acidulants, polysaccharide polymers, chilling injury protectants, plant growth regulators etc. These compositions function by sealing surface pores thus reducing gas permeability and loss of moisture. 15 Further on drying they create a film on the fruit or vegetable surface which provides a desirable shine. These compositions are formulated to sustain these features even during extreme storage conditions.
[003] Post- harvest loss caused by micro-organisms and fungal infection is of 20 particular concern. The current methods for preventing or reducing fungus related post-harvest loss involve addition of synthetic fungicides such as imazalil, sodium ortho-phenylphenate, thiabendazole pyrimethanil, azoxystrobin, or fludi-oxonil to
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the prior art coating formulations. However, these fungicides are toxic to humans and the environment. Further, the currently available food coating compositions are expensive. There is a need for safer edible food coatings that do not use fungicides or other toxic compounds. There is a need for edible food coatings that are more cost effective. 5
SUMMARY OF THE INVENTION
[004] The present invention addresses the afore described needs by providing in one embodiment an edible coating comprising a glazing agent wherein the glazing agent is selected from shellac, bees wax, polyethylene wax, a montanic acid 10 derivative, a resin of plant origin, a wax of plant origin, and a combination thereof; an adjuvant wherein the adjuvant comprises an organic acid and derivatives of the same and an enzyme; an emulsifier wherein the emulsifier is selected from a medium chain fatty acid ester and derivatives of the same, a long chain fatty acid ester and derivatives of the same, and a combination thereof; an edible clay; and a 15 micro-organism selected from Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus salivarius, Lactobacillus plantarum, Streptococcus thermophilus, Saccharomyces boulardii, Bacillus cereus, Pseudomonas eucalypticola, Pseudomonas fluorescens, and a combination thereof. 20
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[005] According to another embodiment the invention is a food coated with the instant coating wherein the food is selected from a fruit, a vegetable, an animal feed, a meat, and any other food material.
[006] According to yet another embodiment the invention is a method of preparing 5 the edible coating, said method comprising sonicating at 90-150C the glazing agent, the edible clay, and the emulsifier to produce a homogenized mixture; and adding the adjuvant and the micro-organism to the homogenized mixture to obtain the edible coating.
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DETAILED DESCRIPTION OF THE INVENTION
[007] The micro-organisms used in the working examples of the instant invention were commercially purchased from China.
[008] In the following detailed description, reference is made to the accompanying 15 working examples that form a part hereof, however these examples are not limiting as the specific components can be adjusted by those skilled in the art without departing from the scope of the invention. The embodiments are described in sufficient detail to enable those skilled in the art to practice the invention and it is understood that other embodiments may be utilized and that changes may be made 20 without departing from the scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. Accordingly, the description and working examples are to be regarded in an
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illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present teachings.
[009] The terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and 5 consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by their equivalents. It is to be understood that the singular forms “a,” “an,” and “the” include plural referents 10 unless the context clearly dictates otherwise. It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 15
[0010] The instant invention intends to address the afore stated technical and economic disadvantages by providing an edible coating comprising a glazing agent wherein the glazing agent is selected from shellac, bees wax, polyethylene wax, a montanic acid derivative, a resin of plant origin, a wax of plant origin, and a 20 combination thereof; an adjuvant wherein the adjuvant comprises an organic acid and derivatives of the same and an enzyme; an emulsifier wherein the emulsifier is selected from a medium chain fatty acid ester and derivatives of the same, a long
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chain fatty acid ester and derivatives of the same, and a combination thereof; an edible clay; and a micro-organism selected from Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus salivarius, Lactobacillus plantarum, Streptococcus thermophilus, Saccharomyces boulardii, Bacillus cereus, 5 Pseudomonas eucalypticola, Pseudomonas fluorescens, and a combination thereof.
[0011] The instant invention contains a glazing agent selected from shellac, bees wax, polyethylene wax, a montanic acid derivative, a resin of plant origin, a wax of plant origin, and a combination thereof. Waxes of plant origin includes but is not 10 limited to carnauba wax, candelilla wax, and rice bran wax. Resins of plant origin, includes but is not limited to colophony and esters of colophony. The glazing agent prevents loss of moisture, thus shrinkage, from the surface of the food by forming a protective coating. The glazing agent also provides a glossy appearance to the food. 15
[0012] The instant invention also contains an emulsifier wherein the emulsifier is selected from a medium chain fatty acid ester and derivatives of the same, a long chain fatty acid ester and derivatives of the same, and a combination thereof. In one embodiment of the coating the long chain fatty acid is palmitic acid or stearic acid 20 and the medium chain fatty acid is lauric acid. Derivatives of the fatty acid includes but is not limited to mono and diglycerides of fatty acids, sucrose esters of fatty acids, polyglycerol esters of fatty acids, glycerol or sorbitol or sucrose ester of the
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fatty acid. Emulsifiers are used in coating formulations, as they enable hydrophobic ingredients to actively engage with hydrophilic elements such as water and spread over a larger surface area. This helps the hydrophobic ingredients to perform actively at much lower concentrations or dosages, leaving very low residues on the surface of fruits and vegetables. The key function of the emulsifiers of this invention 5 is to blend/ disperse the glazing agents, adjuvants and other ingredients into a homogeneous mixture with the desired properties and solubility in water or alcohol.
[0013] In one embodiment the instant coating comprises a micro-organism selected from Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus casei, 10 Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus salivarius, Lactobacillus plantarum, Streptococcus thermophilus, Saccharomyces boulardii, Bacillus cereus, Pseudomonas eucalypticola, Pseudomonas fluorescens, and a combination thereof. The instant coating uses micro-organisms as bio-control agents. Use of the micro-organism allows avoiding the use of fungicides in the 15 composition. The composition may contain a fungicide in one embodiment. The micro-organisms act as antagonists to prevent the growth of other micro-organisms, particularly pathogenic organisms. However, the micro-organisms lose their viability, thus lose their ability to protect against post-harvest loss, when combined with the ingredients typically used in post-harvest fruit treatment such as, the 20 glazing agents, emulsifier, preservatives, alkaline agents, and others.
[0014] The instant coating prevents this loss of microbial viability by providing adjuvants that help the micro-organisms to remain viable in the presence of the
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other ingredients. The adjuvant is an ingredient when added as a small percentage of the total formulation performs a certain function in combination with other ingredients. This certain function is to support growth of the micro-organisms when in presence of the other ingredients and when they are applied on the surface of fruits or vegetables or any other food material. The adjuvant also functions to 5 enhance the properties of other ingredients, to act as a suitable preservative, antioxidant and acidity regulator. In the instant invention the adjuvant comprises an organic acid and derivatives of the same and an enzyme. In one embodiment of the coating the organic acid is selected from ascorbic acid, lactic acid, sorbic acid, acetic acid, formic acid, propionic acid, benzoic acid, citric acid, and a combination 10 thereof. In one embodiment of the coating the enzyme is selected from a protease, a chitinase, an amylase, a xylanase, and a combination thereof.
[0015] The instant coating contains an edible clay that adds to the coatings protective function by reducing food decay. Clay creates a protective surface 15 coating so that pathogenic organisms cannot access the food surface to feed on the surface nutrients. If the pathogens produce toxins, the clay binds to the toxins. In one embodiment of the coating the edible clay is selected from montmorillonite, bentonite, smectite, aluminosilicate, and a combination thereof.
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[0016] In one embodiment of the coating the glazing agent is 5 to 45 % by weight, the adjuvant is 15 to 35 % by weight, the emulsifier is 20 to 40 % by weight, the edible clay is 5 to 15 % by weight, and the micro-organism is 5 to 10 % by weight.
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[0017] In one embodiment of the coating, the adjuvant comprises 10 to 25% by weight of the organic acid and derivatives of the same and 2 to 5 % by weight of the enzyme.
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[0018] In one embodiment the invention is a food coated with the instant edible coating, wherein the food is selected from a fruit, a vegetable, an animal feed, a meat, and any other food material. The food may be fresh or prepared. The meat may be animal or fish meat.
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[0019] The edible coating is soluble in water or in alcohol. The said coating may be dissolved in water or alcohol to a concentration of 15-30%. The present coating may be sprayed on the food surface and allowed to dry.
[0020] In one embodiment the invention is a method of preparing the present 15 edible coating, said method comprising sonicating at 90-150C the glazing agent, the edible clay, and the emulsifier to produce a homogenized mixture; and adding the adjuvant and the micro-organism to the homogenized mixture to obtain the edible coating.
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[0021] Sonication is performed in a vertical or horizontal blender with a high-pressure homogenizer at a pressure of above 150 bar.
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[0022] Thus, this coating effectively increases post-harvest shelf-life by preventing pathogenic growth on the food surface due to the presence of antagonistic bio-control micro-organisms that are in a viable state. The coating increases shelf-life, retains appearance, taste, moisture, and protects the food against pathogens. The instant coating is cheaper than other commercial coatings. Other commercial 5 coatings manufactured outside India cost approximately 3 times more than the present invention, per tonne of fruit or vegetable or food. Further, the instant coating does not require the use of additional protection such as plastic shrink, a further cost per tonne of fruit or vegetable or food.
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[0023] In one embodiment the coating is suitable for commercial packing houses where the drying air temperatures may go above 60C. The composition is formulated to remain functional in conditions which are commonly found in most commercial packing houses across Europe, USA and other countries where fresh fruits are packed for export or consumption. 15
[0024] There are several optional or non-essential ingredients that may be added to the instant composition. Some examples of such optional ingredients are, including but not limited to, sulfites, including sodium sulfite, sodium bisulfite, sodium metabisulfite, potassium bisulfite and potassium metabisulfite, Vitamin E 20 (tocopherol), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), disodium ethylenediaminetetraacetic acid (EDTA), and polyphosphates.
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[0025] The following experimental examples are illustrative of the invention but not limitative of the scope thereof:
[0026] Working Example 1:
The below examples show various embodiments of the instant coating. Example 1 5 of Table 1 tests a coating embodiment for fruits and vegetables. Example 2 of Table 2 tests a coating embodiment for animal feed. Example 3 of Table 3 tests a coating embodiment for feed and fodder. Samples 1, 2, 3 and 4 comprise an emulsifier blend, glazing agent blend, micro-organism blend, clay blend and adjuvant blend in the parts or percentages as stated in Tables 1 to 3. Sample 3 is a prior art coating 10 composition. The coatings were prepared by sonicating the glazing agent blend, the edible clay blend, and the emulsifier blend at 90-150C in a vertical or horizontal blender with a high-pressure homogenizer at a pressure of above 150 bar to produce a homogenized mixture. Next the adjuvant blend and the micro-organisms were added to the homogenized mixture to obtain the edible coating. 15
Table 1:
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Table 2:
Table 3:
The ingredients of the emulsifier blend, glazing agent blend, micro-organism blend, 5 clay blend and adjuvant blend of Tables 1 to 3 are as below. Tables 4 to 8 below show the weight in grams of the ingredients that are mixed together for each blend. The below blends are then used in the parts or percentages as listed in the afore Tables 1 to 3 for Examples 1 to 3.
Table 4: 10
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Table 5:
Table 6:
The microorganisms utilized in the Microorganism cocktail of Table 6 were of a 5 concentration of 5 billion cfu/g and purchased from China.
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Table 7:
Table 8:
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The enzyme activity of the enzymes used in the adjuvant blend of Table 8 is as follows:
Enzyme activity rate of standard enzyme activity products used in Table 8
1. Protease: Enzyme activity: ≥5,000u/g
2. Chitinase: Enzyme activity: ≥5,000u/g 5
3. Amylase: Enzyme activity: ≥5,000u/g
4. Xylanase: Enzyme activity: ≥5,000u/g
The enzymes and micro-organisms were sourced from China, from Shandong Zhongke-Jiayi Bioengineering Co., Ltd and Zhengzhou JDZ Bio Technology Co., 10 Ltd.
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Results:
The coatings of Examples 1-3 of Tables 1-3 were prepared and coated on commercially purchased imported uncoated mango to test for shelf-life extension after mixing in water at a dosage of 300 grams per tonne of fruit and the results are 5 as below. The control in all cases was the fruit, feed or fodder without a coating.
Table 9:
After 10 days storage at ambient temperature:
Table 10: 10
After 20 days storage at ambient temperature:
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After 20 days of storage, sample 1 shows marketability value of 1, moisture loss of 18%, fresh odour and fresh yellow look as compared to the control fruit which rotted (Table 10). Sample 3 which is the prior art composition shows a marketability of 0.2, higher moisture loss and a rotten odour (Table 10). Thus, the edible coating composition of Sample 1 shows a synergistic effect wherein the ingredients work 5 together to provide better shelf-life to the fruit as compared to Sample 3.
Example 2: The prepared coatings were mixed with chicken feed to test for shelf-life extension and nutrient stability after mixing with water at a dosage of 1000 grams per tonne of feed, the results found below are after 120 days of storage at ambient temperature. 10
Table 11:
The Control feed had bad odour and mould growing on them. Sample 1 had no mould, no bad odour and showed a marketability value of 1. Sample 3 the commercially available prior art formulation showed mould spots, bad odour and a 15 marketability value of 0.25. Sample 1 ingredients shows a synergistic effect wherein the shelf-life of the feed is improved over Sample 3.
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Example 3: The prepared coatings were mixed with Livestock Feed to test for shelf-life extension and nutrient stability after mixing with water at a dosage of 1000 grams per tonne of feed. The results below are after 180 days storage at ambient temperature.
Table 12: 5
The Control feed had mould spots and bad odour. Sample 1 shows no mould, fresh odour and marketability value of 1 as compared to Sample 3 (prior art formulation) where the feed had mould spots, bad odour and a marketability value of 0.15. Sample 1 ingredients shows a synergistic effect wherein the shelf-life of the feed is 10 improved over Sample 3.
[0027] Thus, the instant invention comprises an edible coating to be applied on fresh fruits, vegetables, animal feed, meat, or any other food surface. The edible coating is a synergistic combination comprising glazing agent, adjuvant, emulsifier, edible clay and microorganisms. The instant edible coating does not require the use 15 of fungicides. The instant edible coating is cost effective.
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[0028] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims. , Claims: We Claim:
1. An edible coating comprising:
a glazing agent wherein the glazing agent is selected from shellac, bees wax, polyethylene wax, a montanic acid derivative, a resin of plant origin, a wax of plant origin, and a combination thereof; 5
an adjuvant wherein the adjuvant comprises an organic acid and derivatives of the same and an enzyme;
an emulsifier wherein the emulsifier is selected from a medium chain fatty acid ester and derivatives of the same, a long chain fatty acid ester and derivatives of the same, and a combination thereof; 10
an edible clay; and
a micro-organism selected from Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus salivarius, Lactobacillus plantarum, Streptococcus thermophilus, Saccharomyces boulardii, Bacillus cereus, Pseudomonas eucalypticola, 15 Pseudomonas fluorescens, and a combination thereof.
2. The coating as claimed in claim 1, wherein the glazing agent is 5 to 45 % by weight, the adjuvant is 15 to 35 % by weight, the emulsifier is 20 to 40 % by weight, the edible clay is 5 to 15 % by weight, and the micro-organism is 5 to 10 % by weight. 20
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3. The coating as claimed in claim 1, wherein the organic acid and derivatives of the same is 10 to 25 % by weight and the enzyme is 2 to 5 % by weight.
4. The coating as claimed in claim 1, wherein the organic acid is selected from ascorbic acid, lactic acid, sorbic acid, acetic acid, formic acid, propionic 5 acid, benzoic acid, citric acid, and a combination thereof.
5. The coating as claimed in claim 1, wherein the enzyme is selected from a protease, a chitinase, an amylase, a xylanase, and a combination thereof.
6. The coating as claimed in claim 1, wherein the long chain fatty acid is palmitic acid or stearic acid and the medium chain fatty acid is lauric acid. 10
7. The coating as claimed in claim 1, wherein the edible clay is selected from montmorillonite, bentonite, smectite, aluminosilicate, and a combination thereof.
8. A food coated with the coating of claim 1, wherein the food is selected from a fruit, a vegetable, an animal feed, a meat, and any other food material.
9. A method of preparing the edible coating as claimed in claim 1, said 15 method comprising:
sonicating at 90-150C the glazing agent, the edible clay, and the emulsifier to produce a homogenized mixture; and
adding the adjuvant and the micro-organism to the homogenized mixture to obtain the edible coating